OP0065 INFLIXIMAB BIOSIMILAR-TO-BIOSIMILAR SWITCHING IN PATIENTS WITH INFLAMMATORY RHEUMATIC DISEASES: CLINICAL OUTCOMES IN REAL-WORLD PATIENTS FROM THE DANBIO REGISTRY
Authors: H. Nabi, M. L. Hetland, A. G. Loft, O. Hendricks, D. Jensen, J. K. Pedersen, S. A. Just, K. Danebod, H. L. Munk, S. Kristensen, N. Manilo, A. Colic, A. Linauskas, P. H. Thygesen, L. B. Christensen, M. Høgberget Kalisz, N. Lomborg, J. Grydehøj, J. Raun, R. Ahmed, F. Mehnert, N. Steen Krogh, B. Glintborg
Journal: Annals of the Rheumatic Diseases (2022)

Background In routine care, biosimilar-to-biosimilar infliximab switching may occur to save costs (=non-medical switching). Previous studies have investigated the efficacy and safety of switches from originator infliximab to a corresponding biosimilar in patients with inflammatory rheumatic diseases (1). However, the outcomes after switching from one infliximab biosimilar to a second infliximab biosimilar remain scarcely investigated. Denmark has recently conducted a nationwide mandatory infliximab biosimilar-to-biosimilar switch. Objectives To investigate the effectiveness of infliximab biosimilar-to-biosimilar switch (CTP-13 to GP1111) among patients with RA, PsA and AxSpA, including patients who had previously switched from originator (originator-experienced) to CT-P13 as well as patients who were originator-naïve. Methods Observational cohort study based on DANBIO registry (for clinical data upon switch =baseline) linked with national patient registries (to identify prior comorbidities). Patients with RA, PsA or AxSpA who performed a biosimilar-to-biosimilar switch from CT-P13 to GP1111 between April 1 st 2019 and February 1 st 2020 were included. Patient were divided into two groups: originator-naïve and originator-experienced. Main outcomes in the two groups were one-year GP1111 treatment retention (Kaplan Meier “drug survival curves”) and changes in disease activity 4 months before versus 4 months after switch in individual patients. Also, factors associated with GP1111 treatment retention for both groups combined were explored with Cox proportional hazard regression analyses, stratified by diagnosis (univariate-, age-and gender adjusted and fully adjusted). Analyses were adjusted for relevant clinical factors (for details: see Table 1) Table 1. Baseline variables associated with GP1111 withdrawal (RA shown below, similar findings for PsA and AxSpA) Univariate Age- and gender adjusted Multivariate HR (95% CI ) p-value HR (95% CI ) p-value HR (95%CI ) p-value RA Female gender 0.9 (0.6-1.3) 0.4 - 0.7 (0.5-1.2) 0.2 Age, years 1.0 (0.9-1.0) 0.9 - 1.0 (0.9-1.1) 0.6 Originator-experienced versus originator naïve to infliximab 0.5 (0.3-0.8 ) 0.002 0.5 (0.3-0.8 ) 0.002 0.4 (0.2-0.9 ) 0.01 Methotrexate use, yes 0.5 (0.3-0.7 ) &lt;0.001 0.5 (0.3-0.7 ) &lt;0.001 0.6 (0.4-0.9 ) 0.01 Comorbidities ≥1 1.1 (0.7-1.5) 0.8 1.1 (0.7-1.5) 0.8 0.9 (0.6-1.4) 0.7 In remission (yes) 0.4 (0.3-0.6 ) &lt;0.001 0.4 (0.2-0.6 ) &lt;0.001 0.5 (0.3-0.7 ) &lt;0.001 DAS28 1.7 (1.4-1.9 ) &lt;0.001 1.7 (1.5-1.9 ) &lt;0.001 - - Patient global VAS, mm 1.0 (1.0-1.1 ) &lt;0.001 1.0 (1.0-1.1 ) &lt;0.001 - - Results In total, 1,605 patients underwent an infliximab biosimilar-to-biosimilar switch and were included; 1,171 were originator-naïve and 434 were originator-experienced, 685 RA/314 PsA/606 AxSpA, median disease duration was 9 years, 42% were in DAS28/ASDAS remission at the time of switch. At one year, 83% (95% CI 81-85) of the originator-naive and 92% (95% CI 90-95) of the originator-experienced switchers maintained GP1111 treatment (Figure 1). Changes in disease activity 4 months pre- and post-switch were close to zero for all disease activity measures (e.g. DAS28, ASDAS, VAS pain, not shown). The risk of GP1111 withdrawal was lower in originator-experienced compared to originator-naïve patients in patients with RA and PsA: HR 0.4 (95% CI 0.2-0.9, p-value 0.01) and HR 0.1 (0.1-0.6, p=0.01), but not significantly for AxSpA 0.56 (0.27-1.13, p=0.1). Across all indications, lower disease activity at baseline (DAS28/ASDAS remission) was associated with higher retention (Table 1). Conclusion Biosimilar-to-biosimilar infliximab switch was effective and well-tolerated in &gt;1,500 real-world patients. Retention was higher in originator-experienced switchers and patients, who were in remission at the time of the switch, suggesting retention to be more affected by patient-related than drug-related factors. References [1]Glintborg et al , ARD , 2017; 76: 1426–1431 Acknowledgements We thank departments reporting to the DANBIO registry. Disclosure of Interests Hafsah Nabi Grant/research support from: Research grant from Sandoz, who had no influence on the analysis, interpretation and presentation of data., Merete L. Hetland Speakers bureau: Biogen, Celltrion, Janssen Biologics B.V, MSD, Pfizer, Samsung Biopis, Consultant of: Biogen, Celltrion, Janssen Biologics B.V, MSD, Pfizer, Samsung Biopis, Grant/research support from: AbbVie, Biogen, BMS, Eli Lilly Denmark A/S, Lundbeck Fond, Pfizer, Roche, Sandoz, Novartis, Anne Gitte Loft Paid instructor for: AbbVie, Eli Lilly Denmark A/S, Janssen- Cilag A/S, MSD, Novartis, Pfizer, UCB, Consultant of: AbbVie, Eli Lilly Denmark A/S, Janssen-Cilag A/S, MSD, Novartis, Pfizer, UCB, Grant/research support from: Novartis, Oliver Hendricks Speakers bureau: AbbVie, Pfizer, Novartis, Dorte Jensen: None declared, Jens Kristian Pedersen: None declared, Søren Andreas Just: None declared, Kamilla Danebod: None declared, Heidi Lausten Munk: None declared, Salome Kristensen: None declared, Natalia Manilo: None declared, Ada Colic: None declared, Asta Linauskas: None declared, Pia Høger Thygesen: None declared, Louise Brot Christensen: None declared, Maren Høgberget Kalisz: None declared, Niels Lomborg: None declared, Jolanta Grydehøj: None declared, Johnny Raun: None declared, Rabiah Ahmed: None declared, Frank Mehnert: None declared, Niels Steen Krogh: None declared, Bente Glintborg Grant/research support from: BMS, Pfizer, Sandoz.